Electrical steam and hot-water boiler



N. R. FORSSBLAD. ELECTRICAL STEAM AND HOT WATER BOILER.

, APPLICATION FILED JUNE 10, I920.

Patented Aug. 2,1921.

UNITED STATES PATENT OFFICE.

m RICHARD ronss'BLAn, or vAsrERAs, SWEDEN.

ELECTRICAL STEAM AND HOT-WATER BOILER.

To all whom it may concern:

Be it known that I, NILs' RICHARD Fonss- BLAD civil engineer, subject of the King of Sweden, residing at Vasteras, in the Kingdom of Sweden, have invented certain new and useful, Improvements in Electrical Steam and Hot-Water Boilers, for which I have filed an application in weden, Nov. 14, 1918,) of which the following is a specification.

The present invention relates to such steamor hot water boilers in which the steam is, roduced by an electrical current passing irectly between electrodes sub- .merged in the water.

In all boilers of the type herein considered the electrodes will have to be surrounded by tubes of some insulating material, in order to prevent direct short circuits between the electrodes. The control of the output, which is generally wanted, was heretofore obtained mostly by disconnecting one or more electrodes by means of a plurality of switches arranged outside the boiler.

Accordin to the present invention the control of t e output is effected by raising or lowering the insulatin tubes surrounding the electrodes, whereby tfie length and thereby the resistance of the water columns within the tubes is varied. By this arrangement the output of the boiler may, thus be varied within certain limits without changing the number of electrodes connected in circuit. Therefore, the number of electrodes answering certain requirements for control need not be as large as in the constructions heretofore employed, and this, evidently, contributes to a reduction of the costs for the boiler as compared with rior s stems.

Two embodiments of t e boi erare illus trated in the accompanying drawing, where- 1n--- 7 Figures 1-3 show an upright boiler with six electrodes, while Figs. 4' and 5 disclose a horizontal boiler with three electrodes. Fig. 1 is a vertical section on line A-A, and Fig. 2 a vertical section on line B--B in Fig. 3. Fi 3 is a horizontal section on line (L-C in ig. 1. Figs. 4 and 5 are similar longitudinaland cross sections respectively.

The shell of the boiler is designated by 1. The numeral 2 denotes the electrodes, 3 the inlet ducts, 4 the insulating tubes and 5 a contrivancefor keeping these'tub'es together. I 6 are ropesby means of which the Specification of Letters Patent. Patented Aug. 2, 1921. Application filed June 10, 1920. Serial No. 388,033.

vicefor the ropes, such device consisting of a rotatable shaft and operating meansin the form of a hand wheel. Arrangements other than the one herein disclosed may obviously be used for raising and lowering the pipes 4, such arrangements comprising for example devices operated by tooth racks or levers.

The mode of operation of the boiler is as follows: The electrical current, preferably a multiphase alternating current, is led into the boiler at the lower side thereof through the inlet ducts '3 and to the electrodes '2, and the current then passes through the water between the electrodes. According as the tubes 4 are raised or lowered by means of the ropes 6 and the shaft 7 ,the resistance of the water between the electrodes varies, and consequently also the output of the boiler Varies.

The electrodes may be ofany form suitable for the purpose but preferably they are ball-shaped. Generally, they should have a relatively short length in the longitudinal direction of the surrounding tube.

The tubes are preferably open at both ends, so as to allow of a free circulation of the water and to allow the circuit to be closed evidently be used also in boilers employed only for the purpose of heating water.

What I claim as new and desire to secure by Letters Patent of the United States is 2- 1. A method of controlling the output of electrical steam or hot water boilers of the type wherein the heat is produced by passing an electric current through the water between submerged electrodes each surrounded by an insulating tube, consisting in varying the length of the inclosed columns of water passed by the current by displacing the tubes axially relatively to the electrodes.

2. An arrangement for controllingthe outputof electrical steam or hot water boilers comprising a plurality of submerged electhe length of the inclosed columns of water 5. An arrangement of the kind defined by 15 claim 2 in which the electrodes are open at both ends.

6. An arrangement as claimed in claim 2 in which the active parts of the electrodes are of substantially ball-shape and of rela- 20 tively short length.

In testimony whereof I atlix my signature in presence of two witnesses.

NILS RICHARD FORSSBLAD.

lVitnesses HELGE ANDEMAN, Lumos NEOLIN. 

